I'm just viewing this now, sorry to get back to you so late. That rear anchor trolley is installed using a harken pulley system, with the holes drilled out to fit two bolts which mount to well nuts. There's no pressure on the system, so well nuts are fine. I fish all the time using this system in the spring, it has never failed. You also want the trolley to be set just above the water line, this allows your kayak to be more stable in chop. The higher the anchor trolley, the more you will get rocked around. just a heads up.